Toothbrush



May 20, 1941. w ow 7 2,242,743

TOOTHBRUSH Filed May 15, 1959 M1 I f iiiiiiliii I Patented May 29, 1941TOOTHBRUSH Donovan W. Brown, Huntington, Ind., assignor of one-half toJoseph T. McCarthy, Uhicago, Ill.

Application May 15, 1939, Serial No. 273,619

6 Claims.

This invention relates to an improvement in toothbrushes, and moreparticularly to the arrangement and construction of the bristles of thetoothbrush.

One object of my invention is to provide a toothbrush, the bristle tuftsof which tend to adapt themselves to the contour of the surfaces of theteeth, and which readily reach into the irregularities found on thesurfaces of the teeth as well as the spaces between them.

Another object of my invention is to provide a toothbrush which assiststhe user in the proper brushing of the teeth.

Another object of my invention is to provide a toothbrush which readilyadapts itself to the contour of the surfaces of the teeth, and whichenters the irregularities and spaces found between the teeth with theminimum amount of pressure, thus lengthening the life of the bristles.

A more specific object of my invention is to provide a toothbrush havinga working surface comprising a series of transverse inverted V- shapedgrooves, each constituted by oppositely beveled upper surfaces ofbristle tufts secured at an angle to the brush handle and crossing eachother intermediate their ends.

Other objects and advantages of my invention will appear more fully fromthe following description, during the course of which reference is madeto the accompanying drawing, in which:

Fig. 1 is a side elevational View of a toothbrush embodying myinvention, showing the bristles of the brush in contact with a dentalarch;

Fig. 2 is a side elevational view of a toothbrush is indicated in itsentirety by reference character I0. It may be seen to comprise a handleportion l2, preferably made of rigid material in accordance withcustomary practice. The forward or head portion 14 of the handle hassecured to it a plurality of outwardly extending tufts l8 of suitablebristles. The head l4 may be dimensioned and shaped to suit the user ormanufacturer, and this is true to a certain extent of the bristle tuftsIS.

The bristles are constructed and arranged on the head of the brush toprovide a series of transverse, broad, inverted V-shaped areas on theworking surface, as indicated by the reference character l8.Furthermore, the bristles are arranged at an angle with respect to thebrush head and handle so that when working pressure degrees, and theobtuse angle as approximately degrees. These values are the preferablevalues, and they may be varied somewhat. The tufts are so located withrespect to each other that they cross intermediate their ends, and theouter ends are beveled in a manner now to be described.

The working ends of the tufts are beveled to provide the invertedV-shaped working areas previously referred to. The ends 24 of the tuftsin row 20 are beveled. toward the handle 12 and the ends 26 of the tuftsin row 22 are beveled in the opposite direction, that is, away from thehandle. In other words, the bevel may be considered to be in a directionopposite to the direction in which the tuft slopes. The bevels are sodesigned that the acute angle between the surfaces thereof and a planepassing along the topmost part of the tufts is approximately 25 degrees.The angle included in the V is thus approximately 180 minus 50 ordegrees. Here again the values given are the preferred values and may bevaried.

The many advantages of the brush of my invention may perhaps be bestnoted from a consideration of the action of the brush when utilized inbrushing the teeth. Referring first to Fig. 1 wherethe brush isillustrated in light contact with the dental arch, it may be noted thatthe transverse V-shaped grooves are so dimensioned that they fit thetooth contours with considerable accuracy, and that when pressure isapplied to the brush, the bristles bend and slide along the surface ofthe teeth and reach into the irregularities in the individual toothsurfaces and in between adjacent teeth. The pressure required to forcethe bristles into the position indicated in Fig. 2 is relatively light,because the bristles bend and slide along the surfaces of the teeth. Oneof each pair of tufts defining an inverted V-shaped groove move inopposite directions. The construction, therefore, eliminates crinklingof the bristles and provides a more perfect working contact by slightbending of the individual bristles of each tuft.

The construction of the toothbrush with a series of relatively broad,transverse, inverted V- shaped grooves facilitates correct brushmanipulation when the Charters method of brushing is used. This method,as well known to those skilled in the art, comprises moving the brush upand down.

Maximum cleansing is provided by the angular relation between the toothsurfaces and the bristles, and the bristles adapt themselves to surfaceswhich are irregular or uneven with a minimum of pressure. A longer brushlife is insured because of the slight amount of pressure required andthe resulting decreased strain on the bristles. The decrease in pressurelikewise eliminates crinkling of the bristles.

The brush also guides itself into the areas needing brushing; that is,the spaces between the teeth and the hollows or irregularities on thesurfaces of the teeth. A further advantage of the brush is that thetufts spread out freely during use, thus creating a larger working area.

The above-described embodiment of my invention has been included hereinfor the purpose of illustration only, and modifications thereof mayoccur to those skilled in the art. Among these modifications may bementioned the variation of the angle of the tufts with respect to thebrush and the angle included in the transverse grooves. As a matter offact, certain advantages of my invention may be realized withoutproviding any transverse grooves whatever. Furthermore, instead ofhaving two rows of bristle tufts, a greater number of rows may beutilized.

What I claim as new and desire to secure by United States Letters Patentis:

1. A toothbrush comprising handle and head portions, parallel rows ofbristle tufts secured to said head portion and projecting outwardlytherefrom, the tufts in one of said rows being secured to the headportion at an acute angle with respect to said handle portion, and thetufts in another row being secured to said head portion at an obtuseangle with respect to said handle, and the outer end of each of saidbristle tufts being beveled inwardly in a direction opposite to thedirection in which the tuft slopes at an angle such that the workingsurface is at an acute angle with respect to a plane passing along theouter extremities of the tufts.

2. A toothbrush comprising handle and head portions and parallel rows ofbristle tufts secured to said head portion, the tufts in one of saidrows being secured to said head portion at an angle opposite to that atwhich those in a second row are secured to the said head portion, andeach tuft in one row crossing a tuft in another row longitudinally ofthe brush and intermediate the ends of the tufts, and the outer ends ofsaid tufts being beveled in directions opposite to the slope of thetufts to define working surfaces located at acute angles with respect toa plane passing along the outer extremities of the tufts.

3. A toothbrush comprising a handle portion and a head portion, bristletufts mounted on said head portion providing a working surfaceconsisting of a series of transverse, inverted V-shaped grooves, eachgroove comprising the tips of a pair of tufts secured at an angle to thebrush and crossing each other intermediate their ends, the tips of saidtufts being beveled oppositely across the entire widths thereof.

4. A toothbrush comprising handle and head portions, and parallel rowsof bristle tufts secured to the head portion and projecting outwardlytherefrom, the tufts in one of said rows being secured to the headportion at an acute angle with respect to said handle portion and thetufts in another row being secured to said head portion at an obtuseangle with respect to said handle portion, the outer end of each of saidbristle tufts being beveled in a direction opposite to the direction inwhich the tuft slopes to define plane working surfaces disposed atangles of approximately 25 degrees to a plane passing along the outerends of the tufts.

5. A toothbrush comprising handle and head portions, and two parallelrows of bristle tufts secured to the head portion and projectingoutwardly therefrom, the tufts in one of said rows being secured to thehead portion at an angle of approximately degrees with respect to saidhandle portion and the tufts in the other row being secured to said headportion at an angle of approximately degrees with respect to said handleportion, the outer end of each of said bristle tufts being beveled in adirection opposite to the direction in which the tuft slopes to defineplane working surfaces disposed at angles of approximately 25 degrees toa plane passing along the outer ends of the tufts.

6. A toothbrush comprising handle and head portions, and two parallelrows of bristle tufts secured to the head portion and projectingoutwardly therefrom, the tufts in one of said rows being secured to thehead portion at an angle of approximately 65 degrees with respect tosaid handle portion and the tufts in the other row being secured to saidhead portion at an angle of approximately 115 degrees with respect tosaid handle portion, each tuft in one row crossing a tuft in another rowlongitudinally of the brush and intermediate the ends of the tufts, andthe outer end of each of said bristle tufts being beveled in a directionopposite to the direction in which the tuft slopes to definelongitudinally spaced apart plane working surfaces disposed at an angleof approximately 25 degrees to a plane passing along the outer ends ofthe tufts.

DONOVAN W. BROWN.

